How do I link up 2 computers to one printer

My Desktop computer crashed,but,I was able to recover everything except linking the Desktop PC to my Laptop for Printer Sharing. The way I set up my Laptop now is that if I have to print anything, I pull the USB out of my Desktop and plug it into my Laptop, which is ridicules. I’ve tried Printer Sharing from my Desktop, but, I’m not geting anything. There’s a step I’m leaving out,but, I just don’t remember. The Laptop,Desktop and printer are all within 4 feet of each other,but, if I want to use the laptop with my PCI Card upstairs to print, I can’t.
I’m on a Cable Modem and Wireless Router.
Any information will be greatly appreciated.
Thanks.
jeff